# Sample Visio diagram: Firewall -> Load Balancer -> Web Servers -> Database
# Auto-discovers stencils
# Works on Windows PowerShell 5.x

$ErrorActionPreference = "Stop"

# Output
$docName = "WebApp-LB-Firewall-DB.vsdx"
$outPath = Join-Path $HOME "Documents\$docName"

# Start Visio
$visio = New-Object -ComObject Visio.Application
$visio.Visible = $true

# New document/page
$doc = $visio.Documents.Add("")
$page = $visio.ActivePage
$page.Name = "Architecture"
$page.PageSheet.CellsU("PageWidth").ResultIU  = 22.0
$page.PageSheet.CellsU("PageHeight").ResultIU = 14.0

# -------------------------------
# Stencil discovery and loading
# -------------------------------

$searchRoots = @(
    "$env:PROGRAMFILES\Microsoft Office\root\Office16\Visio Content",
    "$env:PROGRAMFILES\Microsoft Office\root\Office16\Visio Content\1033",
    "$env:ProgramFiles(x86)\Microsoft Office\root\Office16\Visio Content",
    "$env:ProgramFiles(x86)\Microsoft Office\root\Office16\Visio Content\1033",
    "$env:PROGRAMFILES\Microsoft Office\root\Office15\Visio Content",
    "$env:ProgramFiles(x86)\Microsoft Office\root\Office15\Visio Content",
    "$env:PROGRAMFILES\Microsoft",
    "$env:ProgramFiles(x86)\Microsoft",
    "$env:PROGRAMFILES",
    "$env:ProgramFiles(x86)"
) | Where-Object { Test-Path $_ }

# Keywords to select useful stencils (filename match, case-insensitive)
$stencilKeywords = @("network","server","compute","computer","azure","cloud","firewall","security","database","sql","load","balancer","web","iis")

function Find-StencilFiles {
    param([string[]]$roots, [string[]]$keywords)
    $results = @()
    foreach ($root in $roots) {
        try {
            Get-ChildItem -Path $root -Filter *.vssx -Recurse -ErrorAction SilentlyContinue | ForEach-Object {
                $fname = $_.Name.ToLower()
                foreach ($kw in $keywords) {
                    if ($fname -match $kw) { $results += $_.FullName; break }
                }
            }
        } catch { }
    }
    $results | Select-Object -Unique
}

function Load-Stencils {
    param([string[]]$files)
    $loaded = @()
    foreach ($file in $files) {
        try {
            Write-Host "Loading stencil: $file"
            $loaded += $visio.Documents.OpenEx($file, 64) # read-only
        } catch {
            Write-Warning "Could not load stencil: $file"
        }
    }
    foreach ($docX in $visio.Documents) {
        if ($docX.FullName -ne $doc.FullName) { $loaded += $docX }
    }
    $loaded | Sort-Object FullName -Unique
}

$files = Find-StencilFiles -roots $searchRoots -keywords $stencilKeywords
$stencils = Load-Stencils -files $files

if (!$stencils -or $stencils.Count -eq 0) {
    Write-Warning "No stencil files loaded automatically. Fallback rectangles will be used."
} else {
    Write-Host "`nLoaded stencils:" -ForegroundColor Cyan
    foreach ($s in $stencils) { Write-Host " - $($s.FullName)" }
}

# -------------------------------
# Master selection helpers
# -------------------------------

function List-Masters {
    foreach ($st in $stencils) {
        Write-Host ("Stencil/Doc: {0}" -f $st.Name) -ForegroundColor Cyan
        foreach ($m in $st.Masters) {
            Write-Host ("  - {0} (NameU: {1})" -f $m.Name, $m.NameU)
        }
    }
}

function Get-MasterByPattern([string[]]$patterns) {
    foreach ($st in $stencils) {
        foreach ($m in $st.Masters) {
            foreach ($p in $patterns) {
                if ($m.NameU -match $p -or $m.Name -match $p) {
                    Write-Host ("Selected master '{0}' from '{1}' for pattern '{2}'" -f $m.Name, $st.Name, $p) -ForegroundColor Green
                    return $m
                }
            }
        }
    }
    return $null
}

# Drop master centered at x,y; keep default size; label it
function Add-Device([double]$x,[double]$y,[string]$label,[string[]]$patterns,[double]$fontSize=10) {
    $m = Get-MasterByPattern $patterns
    if ($null -eq $m) {
        Write-Warning ("No master matched patterns: {0}. Using fallback rectangle." -f ($patterns -join ", "))
        $w = 2.0; $h = 1.2
        $shape = $page.DrawRectangle($x - ($w/2), $y - ($h/2), $x + ($w/2), $y + ($h/2))
    } else {
        $shape = $page.Drop($m, $x, $y)
    }
    $shape.Text = $label
    $shape.CellsU("Char.Size").FormulaU = "$fontSize pt"
    return $shape
}

# Simple transparent containers (thin gray outline; sent behind shapes)
function Add-Container([double]$x,[double]$y,[double]$w,[double]$h,[string]$text) {
    $shape = $page.DrawRectangle($x, $y, $x + $w, $y + $h)
    $shape.CellsU("LineColor").FormulaU = "RGB(180,180,180)"
    $shape.CellsU("LineWeight").FormulaU = "1 pt"
    $shape.CellsU("FillForegnd").FormulaU = "RGB(255,255,255)"
    $shape.CellsU("FillForegndTrans").ResultIU = 1.0
    $shape.Text = $text
    $shape.CellsU("Char.Size").FormulaU = "12 pt"
    try { $shape.SendToBack() } catch {}
    return $shape
}

# Connector
function Connect($fromShape,$toShape,[string]$text="") {
    $conn = $page.Drop($visio.Application.ConnectorToolDataObject, 0, 0)
    $conn.CellsU("LineColor").FormulaU = "RGB(60,60,60)"
    $conn.CellsU("LineWeight").FormulaU = "0.75 pt"
    $fromShape.AutoConnect($toShape, 0, $conn)
    if ($text) { $conn.Text = $text }
    return $conn
}

# -------------------------------
# Diagram content
# -------------------------------

# Title
$title = $page.DrawRectangle(1.0, 13.4, 21.0, 13.9)
$title.Text = "Web App Architecture: Firewall -> Load Balancer -> Web Servers -> Database"
$title.CellsU("Char.Size").FormulaU = "14 pt"

# Patterns for official icons (broad to match common stencils)
$patFirewall    = @("Firewall|Security|Shield|Azure.*Firewall")
$patLoadBalancer= @("Load.*Balancer|Application.*Gateway|LB|Azure.*Load.*Balancer")
$patWebServer   = @("Web.*Server|IIS|Server(?! Rack)|Computer|Windows.*Server")
$patDatabase    = @("Database|SQL|Azure.*SQL|DB|Cylinder")

# Containers (optional zones)
$dmz     = Add-Container 1.0 10.8 20.0 2.0 "DMZ (Edge/Ingress)"
$webtier = Add-Container 4.0 6.8 14.0 3.2 "Web Tier"
$dbtier  = Add-Container 8.0 3.5 10.0 2.8 "Database Tier"
$clients = Add-Container 1.0 1.0 6.0 2.2 "Clients"

# Devices (kept at native size; spaced widely)
# Edge/Ingress
$fw      = Add-Device 3.0 11.8 "Firewall" $patFirewall 10
$lb      = Add-Device 8.0 11.8 "Load Balancer" $patLoadBalancer 10

# Web servers (pair)
$web1    = Add-Device 9.5 8.0 "Web Server 1\nIIS" $patWebServer 10
$web2    = Add-Device 13.5 8.0 "Web Server 2\nIIS" $patWebServer 10

# Database
$db      = Add-Device 13.0 4.6 "Database\nSQL" $patDatabase 10

# Clients
$client1 = Add-Device 2.0 1.8 "Client\nPC" @("Desktop|PC|Computer|Laptop") 10
$client2 = Add-Device 5.0 1.8 "Client\nServer" @("Server(?! Rack)|Windows.*Server|Computer") 10

# Connectors (flow: clients -> firewall -> LB -> web servers -> database)
Connect $client1 $fw "HTTPS"
Connect $client2 $fw "HTTPS"
Connect $fw $lb "Allow: 443"
Connect $lb $web1 "HTTP/HTTPS"
Connect $lb $web2 "HTTP/HTTPS"
Connect $web1 $db "SQL (1433/Encrypted)"
Connect $web2 $db "SQL (1433/Encrypted)"

# Save
$doc.SaveAs($outPath)
Write-Host "Saved Visio to: $outPath"